Various waterproof coated fabrics have heretofore been made public; for example, waterproof fabrics coated with a natural or synthetic rubber are practically used for raincoats and other waterproof clothing, tents, tarpaulins and other products. But all of them are less moisture permeable; for example, such a waterproof clothing as raincoat gives an unpleasant feeling in wear due to stuffiness, while in the case of tents or the like there condenses vapor in the interior thereof in their practical use. On the other hand, as a waterproof fabric emphasizing moisture permeability there is a fabric having high woven density with a mere water repellent treatment applied thereto, but its water entry pressure is insufficient, about 100 mmH.sub.2 O/cm.sup.2 at the highest, because it is almost decided by the woven construction and yarn density of the fabric used, and when the durability of water repellency is taken into account, its water-proofness is only temporary, for which reasons such fabric is inappropriate as a practical waterproof fabric.
As a coated fabric having air- and moisture permeability, moreover, there is a fabric coated with a microporous polyurethane layer or a fabric coated with a porous layer obtained by using a synthetic resin with various blowing agents or the like added. The former is produced for example by the so-called wet coagulation method in which a polar organic solvent solution of a polyurethane is applied to a base fabric and then the latter is immersed in water bath to form a microporous polyurethane layer thereon. According to this method, it is easy to form a layer having many fine pores, so air- and moisture permeability can be imparted easily, but it is difficult to attain a necessary and sufficient water-proofness. As an example of method of making the latter, mention may be made of the method in which a solution of a synthetic polymer containing a blowing agent is applied to a base fabric and then the blowing agent is allowed to form by heating or some other means to thereby form a porous layer of the synthetic polymer. According to this method, however, the pores thereby formed are spherical or elliptic, large in diameter and consist predominantly of independent pores, so it is difficult to attain a sufficient air- and moisture permeability though water-proofness is obtained.